When carefully fitted, and inside recoil block is as good than an outside secured one. We have encountered numerous vintage English and German big bores so equipped and even after more than fifty years of usage under severe climates, we have never noticed a stock problem relative to the recoil.
The last one was a take down H&H .375 rifle that has seen thirty years of hard use in Cameroon; I'm pleased to show you the arrangement the London maker used for the inside recoil block.

DORLEAC
www.dorleac-dorleac.com